This invention relates to heat exchangers, and more particularly, to heat exchangers used as oil coolers in vehicular applications.
The use of heat exchangers to cool lubricating oil employed in the lubrication systems of internal combustion engines has long been known. One form of such heat exchanger currently in use is a so-called xe2x80x9cdonutxe2x80x9d oil cooler. These oil coolers have an axial length of only a couple of inches or less and are constructed so that they may be interposed between the engine block and the oil filter, being attached directly to the block in a location formerly occupied by the oil filter. Typically, oil coolers of this type include a multi-piece housing which is connected to the vehicular cooling system to receive coolant, and which contains a stack of relatively thin, disk-like chambers or heat exchange units through which the oil to be cooled is circulated. Examples of such oil coolers are disclosed in U.S. Pat. Nos. 4,967,835; 4,561,494; 4,360,055; and 3,743,011, the entire disclosures of which are incorporated herein by reference.
The above heat exchangers have proven to be extremely successful, particularly in cooling the lubricating oil of an internal combustion engine. The structures of these heat exchangers are relatively simple in design, inexpensive to fabricate and readily serviceable when required. Nonetheless, there is a continuing desire to provide additional advantages in heat exchanger structures, including for example, improved heat transfer characteristics, improved pressure drop characteristics, reduced part count, increased structural integrity and cleanliness, and improved flexibility in the shape, size, and manufacturing processing of the heat exchanger.
It is the principal object of the invention to provide a new and improved heat exchanger, and more specifically, to provide an improved heat exchanger for use in oil cooler and vehicular applications. According to one aspect of the invention, a heat exchanger for exchanging heat between first and second fluids is provided. The heat exchanger has an outer periphery radially spaced from a central axis. The heat exchanger includes a first inlet for flow of the first fluid, a first outlet for flow of the first fluid, a pair of juxtaposed tube segments coiled about the central axis to form a plurality of alternating, concentric coils, a second inlet for flow of the second fluid into the heat exchanger, a second outlet for flow of the second fluid from the heat exchanger, and structure for encapsulating the pair of tube segments to retain the second fluid within the heat exchanger as it flows from the second inlet to the second outlet. The first inlet is located adjacent the outer periphery and the first outlet is located adjacent the outer periphery. One of the juxtaposed tube segments has an end connected to the first inlet to receive flow of the first fluids therefrom. The other of the juxtaposed tube segments has an end connected to the first outlet to deliver flow of the first fluid thereto. The pair of tube segments are connected adjacent the central axis to transfer flow of the first fluid between the tube segments.
According to one aspect of the invention, the pair of tube segments are formed from a unitary tube having a hairpin bend connecting the segments adjacent the central axis to transfer flow of the first fluid between the tube segments.
According to another aspect of the invention, the heat exchanger further includes a manifold connecting the tube segments adjacent the central axis to transfer flow of the first fluid between the tube segments.
According to one aspect of the invention, a heat exchanger is provided for exchanging heat between first and second fluids. The heat exchanger has an outer periphery radially spaced from a central axis. The heat exchanger includes a post substantially centered on the central axis and having an exterior surface with a spiral shaped transverse cross section, a tube segment wrapped about the exterior surface of the post to form spiral shaped tube coils about the central axis for directing the flow of the first fluid through the heat exchanger, an inlet for flow of the second fluid into the heat exchanger, an outlet for flow of the second fluid from the heat exchanger, and structure for encapsulating the tube segment to retain the second fluid within the heat exchanger as it flows from the second inlet to the second outlet.
According to one aspect of the invention, a heat exchanger is provided for exchanging heat between first and second fluids. The heat exchanger includes a pair of header plates for directing flow of the second fluid through the heat exchanger, and a core including a tube segment coiled about a central axis to form a plurality of concentric coils. The tube segment has at least one interior passage for flow of the first fluid. At least one of the coils defines an outermost periphery of the heat exchanger and has a first surface sealed against one of the header plates and a second surface sealed against the other of the header plates. At least one of the coils is sealed against at least one adjacent coil to retain the second fluid within the heat exchanger as it flows about the core.
According to one aspect of the invention, a heat exchanger is provided for exchanging heat between first and second fluids. The heat exchanger has an outer periphery spaced from a central axis. The heat exchanger includes a core surrounding the central axis, and a pair of opposed header plates. The core includes interior passages for receiving flow of the first fluid and exterior surfaces for receiving flow of the second fluid. The core has a pair of oppositely facing sides spaced by a width W along the central axis, with each side being open to the exterior surfaces. One of the header plates overlies one side of the core, and the other header plate overlies the other side of the core. One of the plates has first and second manifold chambers angularly spaced from each other about the central axis for directing flow of the second fluid over the exterior surfaces of the core.
According to one aspect of the invention, the other header plate has a third manifold chamber for directing flow of the second fluid over the exterior surfaces of the core. The first chamber is aligned with the third chamber to direct flow from the first chamber over a first angular segment of the exterior surfaces of the core to the third chamber. The third chamber is aligned with the second chamber to direct flow from the third chamber over a second angular segment of the exterior surfaces of the core to the second chamber. The first and second angular segments are angularly spaced from each other about the central axis.
According to another aspect of the invention, the other header plate includes third and fourth manifold chambers angularly spaced from each other about the central axis for directing flow of the second fluid over the exterior surfaces of the core. The first chamber is aligned with the third chamber to direct flow from the first chamber over a first angular segment of the exterior surfaces of the core to the third chamber. The third chamber is aligned with the second chamber to direct flow from the third chamber over a second angular segment of the exterior surfaces of the core to the second chamber. The second chamber is aligned with the fourth chamber to direct flow from the second chamber over a third angular segment of the exterior surfaces of the core to the fourth chamber. The first, second, and third angular segments are angularly spaced from each other about the central axis.
Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings.